Mechanical Aids : Various types of mechanical aids are used in the mail room. 

These aids are described below : 

Stapling Machines: Staplers are used in the mail room to sealing (closing) the envelops. 

Letter Typing Machines: With the help of typing machine letters (bunch of letters) can be tied together. Letters are kept inside the machine and a thin wire passes around the letters and ties them. 

Franklin Machine: Franklin machine is issued by the post office. The postal authorities put a certain value in it (as requested by the office). This machine puts the stamp on the envelope. The value put (entered) in the machine goes on decreasing as more and more stamps are affixed on the envelopes. At one stage the value inserted in the machine is exhausted and the office has to again request the post office to issue a certain limit. 

Dating Machines: Dating machines are used to put the dates on the letters. When there is number of letters, these dating machines are very helpful on putting the dates on these letters. 

Weighing Machines: A weighing machine is used to ascertain the weight of letters. Post Office charges the postal rates according to the weight of letters. After ascertaining the weight of letters, postage stamps are affixed accordingly. 

Serial Numbering Machines: These machines are used to put serial numbers on the letters, despatch register and office copy of the letter. Respective serial numbers can be given on respective places. After putting a serial number as many number of times, the next serial number automatically changes. 

Addressograph: It is another mechanical device which is used to print address of the addressees on envelopes and wrappers. This device is very useful in cases where the number of letters are sent regularly. Names and address of the persons are embossed on metallic stencils. The different stencils of addressees are placed in the machine. The machine automatically selects the stencil and prints the address of person on the envelope.